Engineering Commons^™

The Evaluation Of Polysulfone Composites As Structural Implants In Orthopaedic Surgery, Howard L. Scalzo

Theses

Two polysulfone composites were evaluated to determine their use as structural implants in orthopaedic surgery. The first composite, carbon fiber reinforced polysulfone (C/PS), was evaluated for environmental degradation in an in vivo and in vitro study. The C/PS composites were implanted subcutaneously in the abdomen of rabbits for the in vivo study and immersed in saline solution at 32° C for the in vitro study. The second composite, hydroxylapatite coated polysulfone (HA/PS), was evaluated for bone ingrowth in an in vivo study, and for attachment strength between the HA and the PS in an in vitro study. Also, two surface …

In Vitro Biocompatibility Study To Determine The Synergistic Effect Of Components For An Artificial Bone Graft Material, Levelle Elise Burr Alexander

Theses

A composite bone graft material which can induce or promote new bone growth has potential orthopaedic applications in the repair of bone defects or the stabilization of surgically implanted devices. This material should be biocompatible, have good handling properties, promote osteoinduction and/or osteoconduction and have a good shelf life. Demineralized bone matrix and bone morphogenetic protein have been demonstrated to promote osteoinduction in vitro and in vivo.

This in vitro study examined the inductive ability of an osteoinductive protein, bone morphogenetic protein, when absorbed on non-active devitalized bone matrix. In culture, fetal rat muscle was grown on powdered rabbit demineralized …

Red Blood Cell Deformability Testing By Using A Rheological Method, Zhenglei Ma

Theses

A rheological model of blood has been used for testing red cell deformability. The result of the testing is characterized by five parameters of the model. We suggested that the rheological behavior of blood is affected by red cell deformability. The result of the parameter C of the model, which is the kinetic rate constant of the structural breakdown of rouleaux into individual erythrocytes induced by shearing, from decreased red cell deformability group higher than that from normal control group lead to a criterion for separating normal subjects from decreased red cell deformability. The easy experiment method of using whole …

Survival Rate Study Of Intrashock Versus Postshock Microwave Rewarming In Rats Subjected To Hemorrhagic Shock, Hani M. Patel

Theses

In search for a more effective treatment for rewarming of profound accidental hypothermia, a comparative survival rate study was conducted of intrashock versus postshock microwave rewarming in rats subjected to hemorrhagic shock. In an anechoic chamber, rats were illuminated with 50 Watts of continuous microwave power supplied by a 915 MHz microwave generator. This frequency corresponds to a free-space wavelength of about 33 cm. The incident-power density was calculated to be about 8.5 mW/cm2, and the whole-body specific absorption rate (SAR) was calculated to be 14.5 W/kg.

The microwave postshock group showed a significantly higher post shock survival rate than …

Digital Image Restoration Using Power Spectrum Equalization Filtering Technique, Debdatta Sen

Theses

Digital deblurring of micro-circulatory images using both homomorphic and power spectrum equalization filtering are considered. An existing homomorphic filter was modified by changing filter parameters. This permitted an image with better contrast to be obtained. The power spectrum equalization approach consists of modeling and characterization of degradation and estimation of the power spectrum of the image using the Welch method. The restoration is considered from the point of view of spatial-frequency domain descriptions of images. Consideration is restricted to degradations arising from additive noise and spatially invariant linear blurring. The filter restores the power spectrum of the image to what …

Changes In Expired End-Tidal Carbon Dioxide During Cardiopulmonary Resuscitation In Dogs: A Prognostic Guide For Resuscitation Efforts, Karl B. Kern, Arthur B. Sanders, William D. Voorhees, Charles F. Babbs, Willis A. Tacker, Gordon A. Ewy

Weldon School of Biomedical Engineering Faculty Publications

Expired end-tidal carbon dioxide (PCO2) measurements made during cardiopulmonary resuscitation have correlated with cardiac output and coronary perfusion pressure when wide ranges of blood flow are included. The utility of such measurements for predicting resuscitation outcome during the low flow state associated with closed chest cardiopulmonary resuscitation remains uncertain. Expired end-tidal PCO2 and coronary perfusion pressures were measured in 15 mongrel dogs undergoing 15 min of closed chest cardiopulmonary resuscitation after a 3 min period of untreated ventricular fibrillation. In six successfully resuscitated dogs, the mean expired end-tidal PCO2 was significantly higher than that in nine nonresuscitated dogs only after …

Management Strategies To Minimize And Reduce Soil Compaction, A. J. Jones, R. A. Wiese, Elbert C. Dickey

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Nature has some built-in processes that reduce soil compaction. They include cycles of wetting and drying, and freezing and thawing.

In the last 20 to 30 years, farming practices have changed drastically. These farming changes have made it more difficult for nature to rejuvenate the soil environment to an optimum condition for crops. Performing field operations on wet soils, using multiple field operations to grow the same crop continuously, and eliminating meadow crops from crop rotations contribute to more extensive and deeper compaction.

Each farmer has the opportunity to make decisions that can keep soils from becoming compacted.

Adoption of …

Evaluation Of Irrigation Planning Decisions, Derrel L. Martin, James R. Gilley, Raymond J. Supalla

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A method is developed to determine optimal irrigation strategies for a single season using crop production functions which incorporate physically based coefficients. The relationship of yield to evapotranspiration is used to develop the yield-irrigation function. The physical parameters used in the production function can be determined from field measurements or various types of computer simulation. Using this approach, the optimal irrigated area and depth of water to apply can be related to prices, costs, and physical parameters. This produces a more general solution than commonly used production functions that depend on limited experimental results. The optimal irrigation depth and irrigated …

The Cost Of Misapplication Of Herbicides, Robert Grisso, Elbert C. Dickey, Larry D. Schulze

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A field survey of 103 private herbicide applicators was conducted during the spring of 1986 in 12 central and eastern Nebraska counties. The results showed that only 30% of the cooperators were applying herbicides within 5% of their intended application rate. Twenty-six percent of the cooperators over-applied herbicides during a single application, with an average cost due to misapplication of $3.11/ha ($1.26/a). If these values were extended over Nebraska, $4.26 million are expended for extra herbicides which were not necessary. The average cost of over application was in excess of $570 per application. Forty-four percent of the cooperators under-applied herbicides …

Organ Doses In Routine Radiographic Procedures, Yang Han

Theses and Dissertations

There is general agreement that the extent of the risk from x-ray examination is related in some way to the radiation dose. As the dose increases, the likelihood of significant biological effects also increases. If a clear correlation between dose and effect is to be established, a convenient and reasonably accurate method of estimating patient’s absorbed doses during common radiographic examinations will be highly needed. A simple method is developed in this project to determine the two important parameters e exposure at skin entrance (ESE) and half value layer (IIVL), which is essential to get reasonably accurate estimates of absorbed …

Performance And Design Of Vegetative Filters For Feedlot Runoff Treatment, Elbert C. Dickey, D. H. Vanderholm

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Installation of a zero-discharge, runoff-control system is one method for solving potential water pollution problems from many feedlot operations. Even though the zero-discharge system is required by regulation in several states, this approach may be economically prohibitive for many small operations. An alternative is to install a vegetative filter system to adequately control the runoff so that violations of water quality standards will not occur during storm runoff. Vegetative filters are systems in which a vegetative area such as pasture, grassed waterways, or even cropland is used for treating feedlot runoff by settling, filtration, dilution, adsorption of pollutants and infiltration. …

Scatchard Analysis Of Methane Sulfinic Acid Production From Dimethyl Sulfoxide: A Method To Quantify Hydroxyl Radical Formation In Physiologic Systems, Charles F. Babbs, David W. Griffin

Weldon School of Biomedical Engineering Faculty Publications

A major impediment to the confirmation of free radical mechanisms in pathogenesis is a lack of direct, chemical evidence that oxygen centered free radicals actually arise in living tissues in quantities sufficient to cause serious damage. This investigation was conducted to validate the use of dimethyl sulfoxide (DMSO) as a quantitative molecular probe for the generation of hydroxyl radicals (HO*) under physiologic conditions. Reaction of HO* with DMSO produces methane sulfinic acid (MSA) as a primary product, which can be detected by a simple colorimetric assay. To develop a method for estimating total HO* production, we studied two model systems: …

Quantitative Effects Of Iron Chelators On Hydroxyl Radical Production By The Superoxide-Driven Fenton Raction, Jean Blair Smith, Joanne C. Cusumano, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Iron bound to certain chelators is known to promote the conversion of superoxide radicals (O2) to hydroxyl radicals (HO') by the superoxide-driven Fenton reaction. The production of HO' by various iron chelates was studied using the reaction of dimethyl sulfoxide and HO' to produce methane sulphinic acid. Methane sulphinic acid was quantified by use of a simple colorimetric assay and used to determine the amounts of HO' produced. Superoxide was generated from 200 M hypoxanthine and 0.05 U/ml xanthine oxidase in the presence of 0-100 M iron and 100 M of each chelator. The results of this preliminary investigation illustrate …

Effect Of Oxygen Concentration On The Formation Of Malondialdehyde-Like Material In A Model Of Tissue Ischemia And Reoxygenation, Steven C. Salaris, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

This study was conducted to explore the functional relationship between oxygen concentration during tissue reoxygenation after ischemia and the extent of postischemic lipid peroxidation, an indicator of reoxygenation injury. Excised rat liver or kidney tissue was rendered ischemic for 1 h at 37°C, minced into 1 mm3 fragments, and then reoxygenated for 1 h in flasks of buffered salt solution containing various amounts of oxygen. Production of malondialdehyde-like material (MDA) was measured to indicate lipid peroxidation. MDA production was minimal at oxygen tensions less than 10 mmHg, increased sharply from 10 to 50 mmHg, and plateaued at approximately 100 mmHg. …

Lethal Hydroxyl Radical Production In Paraquat-Treated Plants, Charles F. Babbs, Jo Ann Pham, Ronald C. Coolbaugh

Weldon School of Biomedical Engineering Faculty Publications

Bipyridinium herbicides, including paraquat and diquat, are believed to act by generating highly reactive, oxygen-centered free radicals within chloroplasts when treated plants are exposed to sunlight. This hypothesis has not yet been confirmed by direct chemical measurements of specific free radicals. We studied paraquat-treated plants using a new method able to detect and quantify formation of highly reactive and deleterious hydroxyl radicals (HO*), in which dimethyl sulfoxide (DMSO) is used as a molecular probe. DMSO is oxidized by HO* to form the stable, nonradical compound, methane sulfinic acid, which can be easily extracted from plant tissue and measured spectrophotometrically. Initial …

Surface Cover Provided By Selected Legumes, John E. Gilley, J. F. Power, P. J. Reznicek, S. C. Finkner

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The use of legumes in conservation tillage systems may yield several benefits including reduced erosion resulting from establishment of surface cover. The effectiveness in furnishing surface cover of 18 plant species seeded on three different dates was evaluated over an 11-month period. For several of the legume species, planting date significantly influenced maximum surface cover and the number of days required to reach maximum cover. For each of the planting dates, hairy vetch achieved maximum cover as rapidly as any other legume and maintained the greatest cover throughout the study period. Relationships for estimating legume surface cover from vegetative mass …

Germ Weight, Germ Oil Content, And Estimated Oil Yield For Wet-Milled Yellow Dent Corn As Affected By Moisture Content At Harvest And Temperature Of Drying Air, Curtis L. Weller, Marvin R. Paulsen, Stephen Mbuvi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A split-plot experimental design was used to determine the effect of moisture content at harvest and temperature of drying air on weight, oil content, and estimated oil yield of corn germs recovered from laboratory wet milling. The effects were determined for a high-yielding hybrid of yellow dent corn widely grown in the corn belt that was hand-picked and hand-shelled. Germ oil content decreased significantly as moisture content at harvest and temperature of drying air increased. Germ weight and estimated oil yield generally decreased as both moisture content at harvest and temperature of drying air increased from 17.2 to 29.6% and …

Determining Crop Residue Cover With Electronic Image Analysis, Elbert C. Dickey, David P. Shelton, G.E. Meyer, K.T. Fairbanks

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Crop residue management is one of the best and most efficient soil conservation methods available to farmers. Determinations of the percentage of the soil surface covered with crop residue are often needed for: soil conservation research; erosion control demonstrations; and maintaining compliance with federal, state, or local soil conservation regulations. A number of methods can be used to estimate residue cover, however, many have limitations. To help overcome some of these limitations, a technique, which uses readily-available microcomputer-related hardware and standard video camera equipment has been developed to estimate crop residue cover from photographic slides. This procedure is relatively rapid, …

Enhancing The Adoption Of Soil Conservation Practices With Targeted Educational Programs, David P. Shelton, Elbert C. Dickey, Paul J. Jasa, David A. Biere

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Two independent, but closely related, grant funded educational programs have been developed and implemented to reduce soil erosion in selected areas of eastern Nebraska, U.S.A. Traditional extension programming methods as well as other more nontraditional approaches have been extensively used. In one program, encompassing 220,000 ha of cropland, annual soil erosion has been reduced by 2.5 Mt and annual fuel savings of 1.5 ML have been achieved through a reduction in the number of tillage operations. During a one-year period in the second project, more than 81,000 m of terraces were constructed, which resulted in an annual soil erosion reduction …

Respiratory Impedances Computed From The Forced Oscillation Technique Using An Esophageal Balloon, Richard Thomas Fisler

Theses

The purpose of this investigation is to develop methodology for the standard measurement and physiological interpretation of lung resistance and compliance using non-invasive forced oscillations techniques and validating these results with standardized esophageal balloon techniques. Application of the forced oscillation technique with an esophageal balloon in place permits partitioning of the respiratory system into the pulmonary system which is of primary interest and the less clinically important chestwall system. Diseased lung states are induced in normal subjects by inhalation of a bronchoconstrictor. The total respiratory (pulmonary plus chest wall) and pulmonary impedances are interpreted using both a linear three element …

Three Dimensional Study Of Macromolecular Leakage Patterns Using Video Image Analysis, Nikhil V. Khimani

Theses

It has long been known that blood - tissue transport of macromolecules in the microcirculation is driven by diffusion. Although two dimensional models fit the experimental data well, the diffusion process is three dimensional.The objective of this research was to establish a three dimensional unsteady state mathematical model for intravascular transport of macromolecules, and suppoi t the theoretical establishment by experimental results.

Three dimensional diffusion of macromolecules through the interstitial space in the hamster cheek pouch was studied, with intravital fluorescence microscopy. After application of bradykinin, the movement of Fluorescein isothiocynate (F.I.T.C.) - labeled Dextrans of average molecular weight 150,000 …

Development Of A Novel Dentin Bonding Agent And Testing For Mechanical Properties, Mircroleakage And Toxicity, Sanjay V. Odak

Theses

In this study a dentin bonding agent based on Tolylene diisocyanatc with o chlorophenol as a blocking agent was tested. Bond strength with dentin was determined using a clinically relevant test method. A comparison was made using commercially available bonding agents and restorative resins. A simulation of microleakage around restorations was performed using a "Silver staining technique". Microleakage was quantified using digital image analysis, and a method was proposed to compensate for the loss of the third dimension during image analysis. Layer-by-layer curing of restorative, and an acid etching technique was used to improve bonding to dentin. The oral LD50 …

An Intelligent Computerized Pulse-Duplicator For The In-Vitro Evaluation Of Prosthetic Heart Valves, John F. Andrews

Theses

A computerized data acquisition system is presented for the in-vitro determination of the hydrodynamic performance of prosthetic heart valves. High speed data acquisition and ensemble averaging techniques are employed to minimize error and provide a standard for data collection and analysis across a wide range of simulated physiologic conditions. Processing algorithms automatically divide the cardiac cycle into phases based on landmarks in the pressure and flow waveforms, with minimal variability and without operator intervention. The contributions of valve resistance, regurgitation, ejection, leakage, and power loss to hydrodynamic performance are isolated for investigation. Phasic power loss analysis is reviewed as a …

Computerized Analysis Of Gastrointestinal Spike Burst Activity, Karthik Krishnan

Theses

This thesis describes a computer algorithm for locating gastrointestinal spike bursts. The algorithm also finds the the number of spikes within each spike burst, the average duration, and average amplitude of each spike burst. The algorithm was applied to the automation of the analysis of the Migrating Colonic Complex.

The algorithm detects the spike burst using threshold, time interval and frequency criteria. The computer program is implemented on a PDP 11/73 digital computer. The operation of the algorithm was tested on animal models to detect the spike bursts, before and after the inducement of certain drugs to alter the colonic …

Simulation Of Aids Patient Detoxification By An Extracorporeal Device And Related Experimental Studies, Mansoor Yusuf Kapadvanjwala

Theses

A simple numerical simulation of an AIDS patient detoxification by an extracorporeal device for the removal of virus has been designed. The mathematical model accounts for healthy white cells (W) attacking and destroying the virus (V), while at the same time the virus attacks and infects certain white cells. The infected white cells (W_i) serve as a site for viral growth, and finally the cell is lysed, releasing a large number of viruses in the blood stream. This model can be used to predict concentrations over a given period for the patient.

The device incorporates an antitwister mechanism …

Biocidal Derivatives Of Catechins, Peter E. Laks

Michigan Tech Patents

Sulfide derivatives of catechins derived from condensed tannins have broad spectrum biocidal characteristics. Epicatechin-4-alkylsulfides and cupric complexes thereof containing up to 20, preferably 5 to 15, carbon atoms are particularly effective biocides against wood rotting fungi and gram-positive bacteria. Such sulfides are prepared by reacting condensed tannin, either in the form of a purified tannin extract or comminuted plant tissue, with an appropriate thiol under mild acidic conditions.

Measurement Of Flow Components On Upland Areas Using Dye Dilution Techniques, S. C. Finkner, John E. Gilley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Dye dilution techniques can be used to measure rill and interrill-to-rill flow rates on upland areas. Procedures and equations for making flow measurements are described along with equations for estimating interrill length and width. If measurements of interrill length and rill width are available, use of simplified flow equations is possible.

Water and dye continuity concepts were utilized to develop generalized interrill-to-rill flow relationships. Measurement of flow from interrill-to-rill areas requires information on the concentration and rate of dye injection, and flow rate and dye concentration on both rill and interrill areas at a downslope sampling location. Dye dilution techniques …

Comparison Of Bulk Density Beneath A Belt Track And Tire, Leonard L. Bashford, A. J. Jones, L. N. Mielke

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Wheel traffic is considered a major cause of soil compaction in production agriculture. Soil compaction depends on initial conditions, load, contact area and tire type and shape at the soil surface. The use of tractors equipped with tracks instead of tires has the potential of reducing soil compaction because of reduced surface contact pressure and difference in load distribution over a relatively long-narrow track. The introduction of a new agricultural tractor equipped with a rubber belt track permits a crawler tractor to compete with a large four-wheel drive tractor in both speed and mobility.
Soil bulk density was measured as …

Fetal Phonocardiography, Jeng-Kwan Lin

Theses

A reliable non-invasive tracking of the fetal heart rate from the maternal abdominal surface could be of significant diagnostic importance in the monitoring of pregnancies, not only for fetal heart rate assessment, but also for the observation of congenital cardiac malformations and transient difficulties during labor. Further, the fetal heart rate recording may be used to assess fetal heart rate variability in the antepartum period of gestation when it is not possible to obtain a fetal scalp lead electrocardiogram.

There are several methods being used to detect the fetal heart rate. Phonocardiography, abdominal electrocardiography and ultrasound cardiography are the three …

3-D Reconstruction Of Microvasculature From High Voltage Electron Microscopy (Hvem) Data, Pradip Kumar Paul

Theses

This is a new method for histoarchitectural and volumetric analyses of cell compartments of microvasculature with the use of a unique combination of computerized 3-D reconstruction and HVEM thick serial cross sections. The technology is potentially a reliable, simple, accurate and fast method. Pioneering work in this area was started by Todd et al. (Circ Res Vol :53 p 319 ;1983) basically using light microscopy, but supported by conventional ultrathin transmission electron microscopy. These techniques are important in that they promise to resolve controversies in terms of evaluating the occurance of hyperplasia and hypertrophy in small resistance vessels in various …